Always zest your lemon before cutting it in half to juice—it's much easier to zest a whole lemon, and you'll capture more aromatic oils for maximum flavor impact.

Toss fresh blueberries in a tablespoon of flour and freeze them for 15 minutes before folding into dough to prevent them from sinking or bleeding into the batter.

Cut cold butter into small cubes and keep it chilled until the last moment—this creates pockets of steam that yield tender, fluffy cookies instead of dense ones.

Mix the wet and dry ingredients just until combined—overmixing develops gluten and results in tough, chewy cookies rather than the desired soft, delicate texture.

Remove cookies from the oven when the edges are set but the centers still look slightly underdone—they'll continue cooking on the baking sheet and stay soft and chewy.